At present, electronic products develop rapidly, with various external interfaces. For a product having a main chip, there are generally external interfaces for charging and communication. However, for a typical electronic product, the charging interface and the communication interface are separated, that is, the communication and the charging are performed by using different signal lines respectively. For this, at least three or more lines are needed and a lot of hardware support is needed, thus wasting resources. Further, most electronic products do not support inverse plugging function. With the continuous improvement of comfort of the products, an interface communication convenient for the user and without limiting inserting direction becomes more and more important. However, if two-line communication is used, how to realize data sending of an electronic product using the two-line communication becomes an urgent problem to be solved for those skilled in the art.